The present invention relates to a wheel component having a cavity for mounting a housing for measurement apparatus.
The pressure and temperature of tubeless tires may be remotely monitored using a radio transmitter within the tire to send signals to a remote display mounted in the interior of a vehicle. The sensing device and the electronic circuitry which includes the transmitter and an antenna are generally contained in a sealed housing to protect the components from physical damage and from contamination such as may occur due to tire mounting lubricants, residual chemicals from tire manufacturing, moist and/or dirty air from air filtering bars, run flat tire lubricants, tire sealants and the like.
At the present time, wireless radio frequency tire monitor sensors may be packaged in plastic housings and attached to the inside or outside of tubeless tire wheels, generally with a large metal hose clamp-like straps around the center of the rim well, inside the tire. A disadvantage of such an installation is that the sensor may be damaged during tire installations and service procedures.
Alternatively, a tire monitor may be attached to the valve stem of a tire, either inside or outside the wheel. However, valve stem transmitters add mass to the valve stem itself, increasing forces on the valve stem assembly, and in some cases jeopardizing the effectiveness of the stem to wheel rim pneumatic sealing. Furthermore, externally mounted valve stem monitors are potentially subjected to road hazards and vandalism. Thus, there is a need for an apparatus and method for protecting a tire monitor or other sensing device from physical damage.
The present invention addresses the above need by providing a wheel component with a cavity for mounting a housing containing a measurement apparatus. The measurement apparatus is protected from physical damage during tire installation or other servicing procedures. Since the measurement apparatus is not attached to a valve stem of a tire, the integrity of the valve stem assembly and pneumatic sealing is not compromised. Also, since the measurement apparatus is not mounted externally to the tire, it is protected from road hazards and other external sources of physical damage.
In accordance with one aspect of the invention, there is provided a wheel component having a sunken cavity in an interior circumferential surface of the wheel component, such component may include the wheel rim or spoke for example, or any other part of the wheel system under pressure. The cavity extends below the interior circumferential surface and is operable to hold an insertable housing. The housing may hold a combined sensing device and transmitter for monitoring and transmitting a physical property such as tire operating conditions which may include inflation pressure, temperature, for example.
Preferably, the wheel component further includes a lock for locking the housing in the sunken cavity. The lock may include a groove in the sunken cavity for engaging a tab on the housing, making the system fastenerless. The lock may be of a snap-on type facilitating automatic assembly of the housing containing the sensing device and transmitter to the wheel component.
Preferably, the housing has a shape complementary to that of the sunken cavity and the wheel component has a recessed shoulder extending about a periphery of the sunken cavity for contacting a lip extending about the housing. Ideally, the lip is positioned on the housing such that a top surface of a top portion of the housing is flush with or below the surface of the wheel component, when the lip is in contact with the recessed shoulder, to avoid interference during tire mounting and removal.
Preferably, the top surface of the housing is permeable to electromagnetic radiation and the housing is operable to hold an electronic circuit operable to transmit electromagnetic radiation through the housing for reception by a receiver located remotely from the wheel component. The electronic circuit may be used to measure a physical property to produce a measured value and transmit the measured value to the receiver.
In accordance with another aspect of the invention, there is provided a method for installing a measurement circuit in a wheel component. The method includes receiving a housing containing the measurement circuit into a sunken cavity in a surface of the wheel component and securing the housing in the sunken cavity. Preferably, the method includes locking the housing in the sunken cavity by engaging a tab on the housing with a groove in the sunken cavity. Receiving the housing in the sunken cavity may be achieved by contacting a lip extending from the housing on a recessed shoulder in the wheel component adjacent the sunken cavity, such that a top surface of a top portion of the housing is flush with or below the surface of the wheel component.
Further aspects of the present invention will be apparent to one of ordinary skill in the art upon reviewing the specific embodiments described in the following detailed description and accompanying drawings.